A battery is formed of individual cells, each of which produces a voltage and current output. The cells are arranged in series or parallel arrays to form the power supply that is capable of producing the required voltage and current output of the power supply.
Cells may be constructed from a variety of materials and configurations, each of which has a particular set of operating characteristics. For example, some constructions may be particularly well suited to supplying current at a consistent voltage over an extended period but unsuitable for high transient loads, whereas others are better suited for such loading. It is usual to select a cell construction best suited to the duty cycle to which it will be subjected.
In many applications the duty cycle is consistent and repetitive allowing a particular cell construction to be used to satisfy the demands. In other applications, the duty cycle may vary dramatically and inconsistently making cell selection more difficult. To further complicate the selection many applications that require high peak currents also have volume and weight constraints, for example power tools, hobby planes and race carts to name a few. A particularly demanding application addressed by the applicants is a powered leg prosthesis where the battery is needed to power an actuator and move the user. For many of those applications that have high peak current requirements, the number of batteries required to satisfy the maximum peak current would not fit inside the available volume. There is thus a need for a compact power supply that can meet varying demands and deliver high quantities of energy within a short amount of time, and fit inside a very limited volume.
Accordingly, it is an object of the present application to obviate or mitigate some or all of the above disadvantages.